This invention relates to a system for supporting blocks such as ceramic blocks which may be catalyst coated within a support framework for flow of a gas therethrough and more particularly to apparatus for mounting the ceramic blocks in a rotary regenerative heat exchanger.
Because of more stringent regulations of nitrogen oxide emissions from combustion sources, various methods are being employed to reduce such emissions. Some of these methods involve changes in the combustion process to reduce nitrogen oxide formation while others involve treatment of the flue gases to remove the nitrogen oxides which have been formed. One of the latter techniques is to catalytically reduce the nitrogen oxides to nitrogen and oxygen.
One of the ways in which a flue gas is catalytically treated is to provide the catalyst in a duct or more likely as a part of a rotary regenerative air preheater through which the flue gas passes. As examples, see U.S. Pat. Nos. 4,678,643 and 5,145,652 and the copending U.S. patent application Ser. No. 945,014 filed Sep. 15, 1992, now abandoned. One of the ways this is done is to provide ceramic blocks with gas flow channels that are coated with a catalyst in the rotor of the air preheater. Also, ceramic blocks may be used in air preheaters for other reasons such as corrosion and fire resistance. Supporting these blocks in an air preheater presents certain problems.